Are compact siren speakers with short sound paths efficient?

[Trebor Cadeau]

How can compact siren speakers project as far as reentrant exponentiahorn speakers whose sound path is much more gradual in diameter and longer?
Does the gradually-increasing sound path diameter couple the sound energy to air better?

Has anyone done tests to measure the dB output from different speakers withe same wattage input?

Is the old, bulky Federal Signal CP100 "bullet" speaker withe longest cone and bell the most efficient and therefore loudest?
(Had one fall from the roof of our fire truck as we.retuning from a brush fire along a washboardirt road.
It had been attached to the roof with three sheet metal screws,I recall.)

Thank you

 

[Pro-Emergencias]

I have the same technical question

Personally, I have the empirical impression that I previously had a set of Whelen UnderPro speakers and swapped them out for a pair of SA315 and I definitely notice a reduction in power output.

Both cases with a 295sda1 siren module.
I'm thinking of going back and reinstalling the old underpro set, with better resonance and projection.

 

[Trebor Cadeau]

Wish we could measure dB output at 100 feet with a meter and compare.
Wilhave to see whathe UnderPro speakers are.

Am considering replacing the Whelen SA315s with Federal Signal TS100s with longer cones from CP100s. If I had CP100s, I would remove thexterior chrome bell and use justhe interior plastic liner which apparently continues thexponential flare.

 

[Pro-Emergencias]

Wish we could measure dB output at 100 feet with a meter and compare.
Wilhave to see whathe UnderPro speakers are.

Am considering replacing the Whelen SA315s with Federal Signal TS100s with longer cones from CP100s. If I had CP100s, I would remove thexterior chrome bell and use justhe interior plastic liner which apparently continues thexponential flare.

The UnderPro are these in the image.

 

[Pro-Emergencias]

Wish we could measure dB output at 100 feet with a meter and compare.
Wilhave to see whathe UnderPro speakers are.

Am considering replacing the Whelen SA315s with Federal Signal TS100s with longer cones from CP100s. If I had CP100s, I would remove thexterior chrome bell and use justhe interior plastic liner which apparently continues thexponential flare.

In your case I would try to use the complete TS100s and see how they fit frontally, if you remove the bells it could also lose resonance and sound forward projection.

 

[CHIEFOPS]

The traditional bell and cone speakers are louder by physical design, especially at highway speeds. I had a Whelen sound engineer explain why to me several years ago and refitted my vehicle with a sugar scoop style speaker and the difference was night and day. An additional drawback to these new compact speakers is depending on the vehicle their vehicle specific mounting brackets place them behind a body or chassis component further obstructing their sound output.

 

[Nolines]

So the sa315 behind my grill held in place by the hood latch mount is good then, cause I was considering moving it to the push bumper and adding another since my bl627 handles 2 at 100 watts each.

 

[firebuff17]

@Nolines
If you have the room for a second speaker (unobstructed) it is a cheap easy upgrade for what I think is a noticeable difference.

 

[Nolines]

What I wish, and I'll have to investigate is does it allow separate tones!?

 

[CHIEFOPS]

So the sa315 behind my grill held in place by the hood latch mount is good then, cause I was considering moving it to the push bumper and adding another since my bl627 handles 2 at 100 watts each.

It will never be as loud as a bell and cone speaker. What car is this?

 

[Nolines]

My 05 cvpi. I have the old cone and large bell speaker I loaned to a friend's son so he could verify his pa300 is working, but that's huge and I don't know how to get that in the grill. Had a deuce of a time trying to remove it from my 96 cv, the salvage company got it out for me.

 

[CHIEFOPS]

Lot of room behind that grill but I don't remember what it takes to get behind it- remove the grill from the header panel? If you're prepared to mount a speaker on the push bumper go with a round bell and cone.

 

[Nolines]

The one I have is large rectangular.

 

[CHIEFOPS]

Personal taste, rectangle/square is fine, I prefer round, the bells are easy to find used and new. I will never use a modern compact speaker again if I can help it, they are so inferior to the bell and cone design.

 

[Nolines]

That's what modern technology is for, making good things small and crappy!

 

[Wailer]

I remember reading somewhere that smaller speakers also led to the introduction of higher pitched electronic sirens. The Federal PA15A series 1E and PA20A series 2E are good examples of early high pitched electronic sirens, and after years of listening to them I found that they sounded best with Federal's TS 24 and TS 100 speakers (the same type of speaker that fit inside the Twin Sonic light bar).

 

[emcom]

Is the ES100C close enough to output of the AS124 federal speaker? They don't publicly list a dB rating which is annoying when trying to compare. I am trying to spec out parts for a 2021 Tahoe build.

 

[SEPD_52]

Is the ES100C close enough to output of the AS124 federal speaker? They don't publicly list a dB rating which is annoying when trying to compare. I am trying to spec out parts for a 2021 Tahoe build.

If you find out, let me know. I'm curious as well. The ES100C is noticeably louder than its predecessor but in my opinion the AS124 is way louder than the ES series.